1. Field of the Invention
The present invention is related to a voltage regulation circuit and method of regulating the voltage and particularly, to a voltage regulation circuit and method of regulating the voltage, capable of generating an optimized bitline precharge voltage and cell plate voltage with regulating a reference voltage without handling the core voltage by controlling a reference voltage generator to adjust the reference voltage in response to a control signal in a test mode.
2. Discussion of Related Art
A bitline precharge voltage is connected to a bitline and used to initialize the bitline in a standby mode of a DRAM, while a cell plate voltage is connected to a plate of a capacitor of a DRAM cell and used to restrain a leakage current by reducing a difference of voltage levels crossing both ends of a cell transistor.
FIG. 1 is a diagram of a conventional voltage regulating circuit generating the bitline precharge voltage and the cell plate voltage.
A reference voltage generator 11 composed of first and second resistors, R11 and R12, in the same size generates a reference voltage Vref of (½)VCORE by dividing a core voltage VCORE during an active mode. A bitline precharge voltage generator 12 and a cell plate voltage generator 13 input the reference voltage Vref and each output a bitline precharge voltage VBLP and a cell plate voltage VLP.
With the bitline precharge voltage generator 12 and the cell plate voltage generator 13, the reference voltage Vref is variable when the core voltage VCORE changes, which makes the bitline precharge voltage VBLP and the cell plate voltage VLP be variable. However, there is a disadvantage that is not able to adjust the bitline precharge voltage VBLP and the cell plate voltage VLP when the core voltage VCORE maintains a constant voltage level.